Certain pharmaceuticals for injection must be stored and transported in a jell format. Unfortunately, these pharmaceuticals in the jell format are too viscous for direct injection. Some of these jells are utilized in chemotherapy.
A preferred jell here used would comprise a cytotoxant and a bulking agent. A preferred low viscosity diluent would comprise a vaso-constricting agent. The jell or high viscosity factor contains a cytotoxin mixed with a biocompatible bulking agent. The diluent or lower viscosity factor comprises a vaso-constrictor to inhibit blood supply to the tumor.
Presence of the bulking agent structures stabilizes the location of the implant within the tumor so as to retain the most effective positioning for the most protracted time period possible. Unfortunately, this effect is of short duration. Thus mixing is required immediately prior to injection. By way of example, a common injected dosage included 9 cc of jell with 0.9 cc of diluent.
The present solution to this problem is to package, store and ship the diluent in one syringe and the jell in another syringe. Immediately before injection, the two separate syringes are opened and connected to a mixing manifold. Thereafter, fluid flow to and from each syringe occurs. Finally, when proper mixing has occurred, substantially all of the mixed jell and diluent is injected to one syringe--for example the syringe that originally transported the jell. Thereafter, injection conventionally occurs.
The manipulation of two separate glass syringes to a separate fitting immediately prior to injection is burdensome and unduly complex for the modern medical environment. What is needed is a unitary assembly which is self contained and user friendly to the required mixing.
In our Haber et al. U.S. Pat. No. 5,211,285 issued May 18, 1993 entitled Telescoping Pharmaceutical Mixing Container, we addressed the problem of the storage and transport of NPH insulin. Simply stated, insulin crystals separate out from carrying fluid during storage. In this disclosure, a smaller inner cylinder and a larger outer cylinder were telescoped and communicated by an apertured plug on the bottom of the smaller inner cylinder. The larger cylinder was closed by a needle piercing septum. The smaller inner cylinder was closed at the proximal end immediate apertured plug by a floating piston forming an air spring with the closed end of the small cylinder.
Mixing occurred by the expedient of leaving the needle piercing septum in place. The small cylinder and apertured plug were depressed into the large cylinder. This depression occurred against the floating piston and air spring of the small cylinder. Air in the air spring was compressed by the floating piston allowing agitating and mixing fluid movement occurred between the small and large cylinders through the apertured plug. When this agitating movement between the large and small cylinder accomplished complete mixing, the needle septum of the large cylinder is ruptured with a needle and the small cylinder depressed. Injection occurs under force of the air spring by depression of the small cylinder into the large cylinder.
This device is not suitable for solution to the present problem of adding diluent to a jell. First, it does not provide for the separate and isolated storage of the medical components. Second, and because injection occurs against the back pressure provided by an air spring, it is suitable for shallow injection only of fluids that are of relatively low viscosity.
As distinguished from this application, the exemplary jell mixed with diluent provides a more complex mixing and injection environment. Isolation of the jell and diluent is required during transport and storage. Further, provision must be made for occasional deep injection, sometimes with needles up to seven inches in length. Such injections cannot occur against the force provided by an air spring.